Clinical Study Of Total Intravenous Anesthesia Combined Propofol With Remifentanil Undergoing One-Lung Ventilation

IntroductionOne-lung ventilation (OLV) is an important part of the modern anesthetic techniques. The intravenous combined with inhaled anesthesia is a traditional anesthetic method of OLV technique,in which the common used volatile anesthetics can depress the effect of HPV, promote V/Q dismatch and increase intrapulmonary shunt(Qs/Qt) undergoing OLV. Total intravenous anesthesia combined propofol with remifentanil can decrease Qs/Qt, while further study about the effects on the respiration, the circulation and the stress of the patients as compare to those of combined inhaled anesthesia during OLV is necessary.Materials and methodsThirty-six ASAâ… -â…¡patients scheduled for elective thoracotomy (18 male, 18 female), aged 18-65 yr, were randomly divided into two groups(n=18 respectively), contrast group (groupâ… ) and experimental group (groupâ…¡). All patients were premedicated with midazolam 5 mg and atropine 0.5 mg im. After arrival in the operation room twoâ…£cannulas were placed to infuse Ringer's lactate solution at 5～10 ml/(kg·h).radial artery was cannulated at upper arm of the operational lateral. The patients were continuously monitored BP, MAP, HR, SpO₂, ECG, CSI, P_ETCO₂ and MAC. Contrast group (groupâ… ) was induced with fentanyl 3μg/kg, propofol 1.5～2 mg/kg and succinylcholine 1.5 mg/kg iv and maintained with inhalated isoflurane (1%-5%), continuously infused remifentanil 0.1-0.2μg/ (kg·min) and intermittent vecuronium 0.02～0.03 mg/kgâ…³. Experimental group (groupâ…¡) was induced with TCI of propofol 2～4μg/ml(plasma concentration), remifentanil 2μg/kg and succinylcholine 1.5 mg/kgâ…³and maintained with TCI of propofol 1-3μg/ml(plasma concentration),continuously infused remifentanil 0.1-0.25μg/ (kg·min) and intermittent vecuronium 0.02～0.03 mg/kgâ…³. The patients were mechanically ventilated after bronchial intubation(RR 12～17 bpm, VT 6～10 ml/kg, I:E=1:1.5～2), CSI was maintained at 38-60.P_ETCO₂ was maintained at 35-45 mmHg.The change of MAP was less than baseline 20 %. Blood samples were taken from the radial artery before anesthesia (T₀), at 5 min before skin incision (T₁), 5 min after skin incision(T₂), 30 min after skin incision(OLV,T₃) and 10 min before the end of operation (T₄) for blood gas analysis and determination of the concentration of Cort,Aâ…¡,INS and IL-6.ResultsThere were no statistical differences between the two groups in age, M/F ratio, body weight, and left/right open thoacotomy ratio et al..SpO₂ (T₃) and PaO₂(T₁, T₂, T₄) in groupâ…¡were significantly increased as compared to those of groupâ… (P＜0.05 or P＜0.01). SBP(T₁), DBP(T₁) and HR(T₁,T₄), Cort(T₃,T₄), Aâ…¡(T₄) and IL-6 (T₁,T₂,T₄) in groupâ…¡were significantly decreased as compared to those of groupâ… (P＜0.05or P＜0.01).DiscussionOLV and surgical stimuli can produce clinically relevant physiological changes of the patients undergoing OLV during combined general anesthesia.The common used volatile anesthetics(enflurane,isoflurane,sevoflurane,desflurane) can depress the effect of HPV,promote V/Q dismatch and increase Qs/Qt.Propofol doesn't inhibited HPV and can protect the lung.Remifentanil is a selectiveμ-opioid receptor agonist with a rapid onset,short duration,and a short blood/effect side equilibration halt time. Because of its unique pharmacokinetics and pharmacodynamic profile,remifentanil is ideally suited for continuousâ…£infusion.The combined propofol with remifentanil is used widely.But its using is little during OLV.In our observation,inâ…¡group the arterial oxygenation of the patients was better, hemodynamic changes were slighter, the substances of the stress were lower than those of groupâ… . There were few complications during and after operation. The finding showed that it was possible cause that:Propofol didn't inhibited HPV,didn't increase V/Q and Qs/Qt too and protected the lung undergoing OLV.Hemodynamic changes responded the stress reaction intermittently and the substances of the stress responded the stress reaction immediately.ConclusionTotal intravenous anesthesia combined propofol with remifentanil can stabilize the respiratory system and the circulatory system,reduce the stress reaction.few complications were seen during and after operation.